Boxaby



L. A. sousoLu. ROTARY CUTTER FOR ROLLER DRILLS. APPLICATION FILED JUNE 16. I919.

Patented Dec. 16, 1919.

- PATENT, OE iQ Louis A; eonnonn, or notrs'ron 'rnxn's.

citizen ofthe United States, residing at by means normircnrriin r012. ROLLER-B31115.-

fccll'wlwmz'tmy concern: l i

Be it known'that I. LOUIS A. .Gon'nonn, a

Houston, Harris oounty,' Texas, hav invented a' certain new and useful Improvement in Rotary Cutters foifRoller-Drills, of which the following is a full, clear, and exact description,'such as will enable others skilled in the art to,which it appertains to make and use the same. 0 Q

- My invention relates to an' improvement in looking meansfor securing a rotary cutterupon its bushing." It has special refer ence to a means of locking the cutter of a rotary drill bit upon the cutter'shaft of the drill. This invention is a modification of my co-pefiding application filed jointly with another of even dateherewith Serial No.

304,508'011 an'improvement in drill cutters for rotary boring drills.

The object of my invention isto provide a means for locking the rotary cutter rotatably-upon its bushing. In this form of-ro-- tary drill the cutter is arranged to inclose the end of. the bushingand the cutter shaft upon which it is mounted, and is retained on said of a locking locking ring isordinarily threaded onto the cutter and 'thereby maintained securely in: contact. therewith so as to retain the cutter on the bushing. In my improvement I eontemplate locking the cutter by meansof a ring which may besprung into a tapered seat in. said ,cutter' and thnsretain the'same' 85 of a threaded to a frusto-conical shaped cutter.

in position. Said is itself retained in expanded position on said cutter by virtue vice.

In the drawings specification I have shownmy preferred em bodiment of this invention, it being understood, however, that slight modifications and changes may be made-herein-without departmgafrom the spirit of the invention therein disclosed. I

Figure 1 is a central longitudinal section illustrating the application of my ilnvention 1 1g. 2 1s plan view, partly di tic,

' the same. Like numer- The cutter disclosed in the is somewhat frusto-conical in shape, having a tapered cutting surface 1, the forward end of which is truncated to provide a flat for- -a apted to contact.

ing 6, said bushing threaded interiorly not. shown. The bushing .6 is cut away tion within the set screw or other similar de-,

' tapered so as to have a wedge effect when forming a part of this "expanded the wlderinnef end of the ring its seat applied to like parts in' Patented Dec. 16, 1919.

ward face 2, also toothed to disintegrate'the mater al cominginto contact therewith. The Inner end of the cutter is also tapered somewhat as shown at. 3 and toothed at 3' todisintegrate material at the side of the hole amst which this jiphrtion of the cutter is ebottom or inner end portion of the cutter is flattened as shown at 4 fO1'. 00Ilt&Ct with an anti-friction washer 5. Y The cutter is provid with a tapered recess on its inner face forming a smooth bearmg surface for rotation upon a tapered bushflattened on the forward end to correspond generally in shape with the cutter. This bushin is upon a shaft or pm 7, WhlCh, in the e ent,.is' integral with the forward end ofthe head 8 of. the bit,

or recessed at 9-on its inner end to provide a seat for a locking ring 10, the cooperat ing inner face of the cutter is also recessed to bear against the outer face of the said locking 10. This cut-away portion 11 is tapered slightly inwardly, asishown in Fig. 1, and the locking 10 is wider This 011 its upper end to. fit, when expanded,

within said tapered recess 11 in the cut ter. The ring 10 is also split in one place, as shownat 12, to provide a space for contracting the ringwhen the same isto be inserted its seat; in the cutter. orderto lock'the ring securely in positapered recess 11, a set screw 13 is used. Adjacent ends of the split ring 10 are rece$ed slightly toprovide a tapered seat for this said set screw. This screw is eaded within the recesses 1n the ends of the lit ring, thereby, forcing them :1, art and li olding the ring expanded firmly into the-seat 11, on the inner face of the cutter. It will thus be apparent that when properly will render it impossible for the ring to be forced from its seat and thus allow the cutter to beiost in the well. 4

It iscontemplatedthat thering can be in the cutter, to hold the cutter and bushing 6 in assembled osition, while the cutter is still in the 3 op. When the cutter, thus locked in position u n the bushing, is shipp to the field, w hzre it is to he used upon e bit, all that will be necessary for the driller to do will be to screw the assembled cutter and bushing upon the threaded shaft 7 of the drill. In order to hold the cutter and locking ring non-rotatably upon the bushing, while the assembled cutter and bushing are being threaded upon the shaft, I have shown a tapered opening 14: in opposite sides of the cutter near the base thereof. This opening extends through the cutter the locking ring and the bushing, so that a tapered pin or wrench 15 may be inserted therein so as to hold these elements, the cutter, the bushing, and locking ring together while the bushing is being threaded on the shaft. When the cutter has been secured in position, the! wrench or pin 15 may be withdrawn and a set screw shown at 16 may be threaded into the alined'openings in the locking ring and the cutter, thereby filling up the opening so as to prevent the entrance of water or grit about the bearings andserving also to lock the cutter and locking ring rotatably together, thus also further securing the looking ring within the recess 11 in the cutter.

In assembling the locking ring within the cutter the bushingwill be-first inserted in position within the cutter and the locking ring 10 will be contracted by having its ends forced tightly together, and in this contracted position its outer diameter will be small enough to pass within the outer diameter of the tapered seat 11 in the face of the cutter. It will then be released and resiliency ofthe ring will force it tightly into its seat. It will then be'locked in expanded position by means of said set screw 13 as previously described. The cutter and lock ing ring will then be rotatable upon the bushing and the cutter will be held against resilient ring in said recesses, and an expanding set screw adapted to retain said ring in expanded position.

2. In a drillbit, a bushing, a cutter thereon, inclosing the end of the same, said cutter and bushing being recessed to provide a seat for a ring, a split ring in said'seat, said ring being wider toward the bottom of said seat, and means to prevent contraction of said ring. a

3. In a roller drill bit, a cutter shaft, a bushing secured thereon, a cutter surrounding the end of said bushing, means to retain said cutter on said bushing comprising an annular groove on the upper adjacent faces of said cutter and said bushing, an expanding ring fitting in said groove and adapted to lock therein and means to retain said ring in expanded position.

In testimonyiwhereof, I hereunto aifix my signature this the 6 day of June, 1919.

, LOUIS A. GODBOLD. 

